Modulational instability (MI) of electromagnetic waves in nonlinear birefringent step-wise decreasing fiber with co-existence
of cubic and quintic nonlinearity is investigated by the coherently coupled nonlinear Schrödinger equation. The
properties of MI gain are studied. The results show that, the procedure occurred not only in the normal dispersion
regime but also in abnormal dispersion regime. The positive quintic nonlinearity index intensifies the modulation
instability, making the width of the gain spectra of MI become wider and the peak gain higher, otherwise, suppresses
the modulation instability, MI gain changes according to the distance propagated, and the gain spectra will change with
token distance series.
This paper presents a Pareto evolutionary artificial neural network (Pareto-EANN) approach based on the evolutionary algorithms for multiobjective optimization augmented with local search for the classification of remote sensing image. Its novelty lies in the use of a multiobjective genetic algorithm where single hidden layers Multilayer Perceptrons (MLP) are employed to indicate the accuracy/complexity trade-off. Some advantages of this approach include the ability to accommodate multiple criteria such as accuracy of the classifier and number of hidden units. We compared Pareto-EANN classifiers results of the classification of remote sensing image against standard backpropagation neural network classifiers and EANN classifiers; we show experimentally the efficiency of the proposed methodology.
The nonlinear Schrodinger equation with variable coefficients is analyzed by means of projection matrix method. An exact analytical solution is obtained, which clearly shows how the variable fiber dispersion, nonlinear, and loss coefficients affect the propagation of ultrashort optical pulses. The obtained solution is used to analyze the propagation properties of ultrashort pulses in dispersion-decreasing fibers. It is found that the ultrashort pulse can realize stable soliton transmission if the fiber dispersions have some certain profiles related to the fiber loss and nonlinear properties. A small variation in the dispersion has a similar perturbative effect to an amplification or loss. The exponentially dispersion-decreasing fiber is studied exemplificatively to demonstrate the obtained results.